I have been trying to setup X with two video cards: G96 Quadro FX580 and an RV380 Radeon X600. I can get the Nvidia card running without a problem. The ATI card always reports the following warning in the Xorg.0.log file: (WW) VESA: No matching Device section for instance (BusID PCI:4:0:0) found. I have tried the vesa driver, the ATI proprietary driver, and the open source drivers. I have the following device section in my xorg.conf file:Section "Device"